1. Technical Field
The present invention relates to an ultraviolet ray curable ink composition for use in an ink jet method (hereinafter, simply referred to as “ultraviolet ray curable ink composition”) and a printed object.
2. Related Art
Conventionally, as a method of manufacturing a trinket showing an appearance having gloss, used is a metal plating, a metal foil press printing using a metal foil, a thermal transfer using a metal foil or the like.
However, there are problems in that a fine pattern is hardly to be formed by using such methods or such methods are difficult to be used for a curved surface portion. Furthermore, the metal foil press printing is difficult to achieve on-demand printing, so that there are problems as follows: It is difficult to supply various kinds of print materials. It is difficult to form metal-texture printing having gradation.
On the other hand, as a method of recording a composition containing a pigment or a dye onto a recording medium, used is a method of recording the composition using an ink jet method. The ink jet method has such advantages as to be able to form the fine pattern or to be used for the curved surface portion. Further, in order to further improve wear resistance, water resistance, solvent resistance and the like of a printed portion, recently, a composition (ultraviolet ray curable ink composition), which includes a polymerizable compound and can be cured due to ultraviolet ray irradiation, is used in the ink jet method (for example, Patent document 1).
However, in the case where metal particles of metal powder are used instead of the pigment or the dye in the ultraviolet ray curable ink composition, there is a problem in that it is difficult to sufficiently exhibit properties such as gloss provided inherently by the metal. In addition, stability (storage stability) of the composition is lowered. This causes a problem in that the composition is turned into a gel, and thus ejection stability of the composition is lowered due to viscosity increase thereof.
Patent document 1: JP-A 2009-57548